Position signal compensation unit of motor, and motor including the same

Abstract

Provided is a motor including a motor driving unit outputting a plurality of switching signals and any one of estimated three-phase voltages, in response to a control signal and a compensated position signal; a pulse width modulation (PWM) inverter outputting three-phase voltages and any one of estimated three-phase currents corresponding to the one estimated phase voltage, in response to the plurality switching signals; a motor unit operating based on the three-phase voltages and outputting a position signal according to the operation; and a position signal compensation unit receiving the position signal, the estimated phase voltage and the estimated phase current, detecting a phase difference between the estimated phase voltage and the estimated phase current and compensating for the position signal in response to the detected phase difference.

What is claimed is: 
     
       1. A motor comprising:
 a motor driving unit outputting a plurality of switching signals and one of estimated three-phase voltages, in response to a control signal and a compensated position signal; 
 a pulse width modulation (PWM) inverter outputting three-phase voltages and one of estimated three-phase currents corresponding to the one estimated phase voltage, in response to the plurality of switching signals; 
 a motor unit operating based on the three-phase voltages and outputting a position signal according to the operation; and 
 a position signal compensation unit receiving the position signal from the motor unit, the estimated phase voltage from the motor driving unit and the estimated phase current from the PWM inverter, detecting a phase difference between the estimated phase voltage and the estimated phase current, and compensating for the position signal in response to the detected phase difference to thereby generate the compensated position signal for the motor driving unit. 
 
     
     
       2. The motor of  claim 1 , wherein the motor unit comprises a plurality of position sensors, and the plurality of position sensors output the position signal based on a position of a rotor that is included in the motor unit. 
     
     
       3. The motor of  claim 2 , wherein the plurality of position sensors are provided based on hall elements. 
     
     
       4. The motor of  claim 1 , wherein the motor driving unit comprises:
 a driving control unit outputting a control signal controlling a reference voltage, in response to the control signal and the compensated position signal; 
 a voltage generating unit generating the reference voltage in response to the control signal and outputting any one of the estimated three-phase voltages based on the reference voltage; and 
 a pulse modulating unit receiving the reference voltage and outputting the plurality of switching signals in response to the received reference voltage. 
 
     
     
       5. The motor of  claim 4 , wherein the driving control unit outputs the control signal that controls a frequency or an amplitude of the reference voltage. 
     
     
       6. The motor of  claim 1 , wherein the three-phase voltages have a form of a sinusoidal wave that includes a harmonic wave. 
     
     
       7. The motor of  claim 1 , wherein the motor unit follows a brushless direct current (BLDC) scheme. 
     
     
       8. A position signal compensation unit of a motor comprising:
 a first comparator receiving any one of estimated three-phase voltages and outputting a voltage signal in response to comparing voltage levels of the received estimated phase voltage and a ground voltage; 
 a second comparator receiving any one of estimated three-phase currents and outputting a current signal in response to comparing current levels of the received estimated phase current and a ground current; 
 a first phase detecting unit detecting a phase difference between the voltage signal and the current signal; 
 a second phase detecting unit detecting phase diagnosis between the voltage signal and the current signal; and 
 a compensation unit receiving a position signal based on a position of a rotor included in the motor and compensating for the position signal in response to the detected phase difference and the detected phase diagnosis. 
 
     
     
       9. The position signal compensation unit of the motor of  claim 8 , wherein the first phase detecting unit comprises:
 a logical operation unit detecting a phase difference between the voltage signal and the current signal; and 
 a counter detecting a count according to the phase difference and outputting the phase difference signal based on the detected count. 
 
     
     
       10. The position signal compensation unit of the motor of  claim 9 , wherein the logical operation unit is an exclusive OR (XOR) logical operator. 
     
     
       11. The position signal compensation unit of the motor of  claim 8 , wherein the phase diagnosis comprises information on whether a phase of the voltage signal leads or lags a phase of the current signal. 
     
     
       12. The position signal compensation unit of the motor of  claim 8 , wherein if a level of the received estimated phase voltage is higher or lower than a level of a ground voltage, the first comparator changes and outputs the level of the voltage signal, and if a level of the received estimated phase current is higher or lower than a level of a ground current, the second comparator changes and outputs the level of the current signal.